Hazuki Yuiga is the younger sister of Nariyuki and Mizuki Yuiga, and the older twin sister of Kazuki Yuiga, sharing the Yuiga surname meaning "solitary".

She appears as a young girl with brown hair cut to ear length and styled in pigtails, complemented by red eyes, consistent with her childlike portrayal.

Within the Yuiga family, Hazuki frequently collaborates with her twin brother Kazuki on matchmaking schemes involving their older brother Nariyuki and his female acquaintances, defining her role in family-centered narratives.

Her name, Hazuki, combines the kanji for "leaf" (葉) and "moon" (月). It traditionally connects to August, signifying "month of leaves" or the older interpretation "month of falling leaves" (葉落ち月).

Available portrayals focus solely on her presence in familial contexts, without exploration of distinct personality traits, specific dialogue, background history, character development, or individual story arcs across the media.